As stated in SEO Web Development, search engines tend to value websites of age over newly established websites. However, if these new sites have clean, well written code, then they have a serious advantage over sites with older, poorly written code. As with most technologies, the newer usually trumps the old. This also applies to how a website is coded. Although older website standards might still be usable, they’re usually not recommended.
The W3C is the World Wide Web Consortium. Established by Tim Berners-Lee, the inventor of the World Wide Web, the W3C does a number of beneficial things for the web. One of their primary tasks is setting code and format standards for websites to follow. Of course, websites aren’t required to follow these standards, but deviating from these recommendations will most certainly penalize your site in regards to search engine rankings.
Of course, not everyone with a website is savvy with HTML, CSS, or other languages. Luckily, the W3C has a validator that will check your website for errors in your code. If errors are found and you’re not sure how to go about fixing them, you may need the assistance of someone familiar with HTML, or a web developer who can rewrite your code in a newer format (with CSS, jQuery, etc).
In addition, just because your site passe W3C validation doesn’t necessarily mean that your code is fully optimized. One example is the frequent usage of tables. Although table-based pages will pass W3C validation, search engines will usually favor the site using new web languages (such as CSS).
Essentially, staying up to date on the latest web standards, and following best practices for code optimization, will give your site the best competitive edge against older sites, and other sites that may not be as observant to the W3 standards as they should.
Code Optimization using Website Auditor
WebSite Auditor has the convenient feature of grabbing your HTML and CSS validation results autonomously. All you need to do is click the Update drop down in the upper left corner, and click Update Ranking Factors for All Pages. Select all the variables you’d like checked, including HTML Code Validation and CSS Code Validation. Depending on your connection and the number of pages to be checked, this could take quite some time. To save time, you can select just one page to update, or head on over to the W3C validator to view the reports directly.
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When viewed from the Webpages tab in WebSite Auditor, the page information will tell you how many warnings and errors for each CSS and HTML that particular page has returned. Clicking on the number underlined in blue will take you to the W3C site to view a detailed report on every error and warning.